To make matters worse, Scotland’s national deficit is now twice the size of the UK’s, with total government spending on Scottish citizens £1,400 higher than the UK average.

So how did this happen? Quite simply: the SNP didn’t see the oil price crash coming. At the beginning of 2014 they budgeted on oil staying above $100 a barrel — now it’s under $40.

This chart shows how drastically Scotland’s oil revenues have fallen in the last five years:

Stv.tvScotland has gone from an oil revenue peak of £10,957,000,000 in 2011/12 to £2,254,000,000 in 2014/15

Scotland’s total tax revenue for the last financial year was £53.5 billion. While oil was once seen as the jewel in the country’s economic crown, at current prices oil accounts for barely 4% of Scotland’s total income.

The declining oil revenues also raises questions about Scotland’s place if Britain decides to leave the EU in a referendum on June 23. The SNP has made it clear it would call for another Scottish independence referendum if Brexit does take place, but these figures will make their challenge to leave the UK significantly more difficult.

NOW WATCH: Money & Markets videos

Want to read a more in-depth view on the trends influencing Australian business and the global economy? BI / Research is designed to help executives and industry leaders understand the major challenges and opportunities for industry, technology, strategy and the economy in the future. Sign up for free at research.businessinsider.com.au.